Autonomous biomedical signals from the central nervous system and functional tissues of the brain are transmitted through corresponding nerve fibers to complete the functions of life actions and activities, such as electroencephalogram. Non-autonomous biomedical control signals are sent by organs to maintain the basic operations of human survival, such as the electrocardiogram. Since biomedical signals are in charge of human life and all activities, it is necessary for us to understand the origin of biomedical signals, the operating principles behind them, and their transmission behavior, and to enumerate common biological signal characteristics, including their amplitude and frequency. Collecting the corresponding biomedical signals can not only understand the biomedical status of the human body in time, but it is also very important to send out early warning signals of symptoms before the onset of the patient’s disease. However, measurement of biological signals may introduce some noise during the process. Therefore, noise must be eliminated first when processing biomedical signals. Only by identifying the characteristics of biomedical signals through signal processing can they become meaningful information and be used for special purposes or applications. For example, rehabilitation aids or equipment can be manufactured through a human–machine interface to improve the quality of life. Implantable devices can also allow patients to immediately apply appropriate feedback, such as implanting a cochlear implant to stimulate the auditory nerve or implanting a pacemaker to stimulate the heartbeat. These signals can also be transmitted wirelessly to a medical center or emergency center to notify relevant units of immediate response and preparation so that patients can receive treatment and immediate care.