Chapter 2 - Biomedical Signals

Abstract

Biomedical signals are collected from a medical or biological source at the organ level, cell level, or molecular level. Different biomedical signals are utilized in the research laboratory, clinic, and sometimes even at home. There are many biomedical signals including the electroencephalogram (EEG), or electrical activity from the brain; evoked potentials, or electrical responses of the brain to specific peripheral stimulation; action potential signals from individual neurons or heart cells; the electrocardiogram (ECG), or electrical activity from the heart; the electromyogram (EMG), or electrical activity from the muscle; sound signals; the electroneurogram, or field potentials from local regions in the brain; the electroretinogram from the eye; and so on (Muthuswamy, 2004). The aim of this chapter is to present widely used biomedical signals in the literature and assist researchers or biomedical engineers in choosing a suitable publicly available biomedical signal database and then guide them toward the interpretation of these biomedical signals. Hence, in each section the reader will find the class(es) of signals, where they are employed, and where these types of signals can be found in public databases. Toward the end of each section, appropriate MATLAB functions useful for analysis are indicated.