Introduction to Biomedical Signals

Diseases or defects in a biological system cause alterations in its normal physiological processes, leading to pathological processes that affect the performance, health, and general well-being of the system. A pathological process is typically associated with signals that are different in some aspects from the corresponding normal signals. This chapter describes the origins and nature of a few biomedical signals of various types, with brief indications of their usefulness in diagnosis. The action potential is the basic component of all bioelectrical signals. The representation of biomedical signals in electronic form facilitates computer processing and analysis of the data. The chapter illustrates the typical steps and processes involved in computer-aided diagnosis and therapy based on biomedical signal analysis. Some of the major objectives of biomedical instrumentation and signal analysis are: information gathering, diagnosis, monitoring, therapy and control, and evaluation.