Knowledge of the biomedical signals is essential in better understanding of the physiological systems. Any variation in biomedical signal characteristics is indicative of
change in the part of the body or system from where it originates. Thus, the origin of
biomedical signals allows understanding the physiological systems more precisely.
This facilitates better diagnosis and monitoring of health conditions by leading to
development of novel methods. In this chapter, biomedical signals which are of most
interest in signal processing techniques have been given focus. The chapter provides
classification of biomedical signals based on different aspects. Then the attention
moves to bioelectrical signals. The role of cell membrane is discussed in generation
of action potential which is the basic building unit of most bioelectrical signals. In
the discussion of major bioelectrical signals; ECG, EMG and EEG, the dynamic
and evoked responses of these signals are also addressed apart from their origin
and basic characteristics. Some other bioelectrical signals such as EOG, ECoG and
EGG are also explained briefly. Finally, the chapter presents an overview of some
non-electrical biomedical signals.