The biomedical signals differ from other signals only in terms of the application — signals that are used in the biomedical field. As such, biomedical signals are produced from a variety of sources. The following is a brief description of these sources: 1. Bioelectric signals: The bioelectric signal is unique to biomedical systems. It is produced by nerve cells and muscle cells. It is produced due to the membrane potential, which under certain conditions may be excited to generate an action potential. In single-cell measurements, the specific microelectrodes are used as sensors, and the action potential itself is considered as the biomedical signal. In more gross measurements, the surface electrodes are used as sensors, and the electric field generated by the action of many cells, distributed in the electrode’s vicinity, constitutes the bioelectric signal. Bioelectric signals are probably the foremost biosignals. The fact that most biosystems use excitable cells makes it possible,
(The Advance Learning Institute of Physics and Technology)