First, what is biofeedback therapy Biofeedback therapy is the application of biofeedback principle in clinical work, and is one of the many methods of psychotherapy. Biofeedback is the use of instruments to process in vivo information related to psychological and physiological activities (such as electromyographic activity, skin temperature, heart rate, blood pressure, brain waves, etc.) and display it to people in a visual or auditory way (i.e. information feedback), and train people to learn to consciously control their own psychological and physiological activities through the awareness of this information, in order to achieve the purpose of adjusting the body’s function, preventing and curing diseases. In short, biofeedback is the use of instruments to understand the information process related to their own physiology and psychology, and learn to control and change these processes at will. Biofeedback therapy is applicable to the medical field, such as the treatment of pediatric ADHD, learning difficulties, childhood mood disorders, depression, anxiety, insomnia, neurosis, stress disorder, obsessive-compulsive disorder, etc. in psychiatry, epilepsy, pain, cerebrovascular disease, etc. in neurology, hypertension, heart disease, diabetes, rheumatism, hyperthyroidism and other psychosomatic diseases in internal medicine, and in rehabilitation. urinary and fecal incontinence, paralysis, disability, etc.; also applicable to the field of education, such as in school counseling centers to deal with examination stress, emotional disorders, Internet addiction, social disorders, suicidal tendencies, etc., or in university psychology departments for teaching demonstration (demonstration of various types of physiological signals), scientific research (collection of different physiological signals to provide effective tools to the subject), etc.; also applicable to the field of sports, such as assisting athletes in activation level regulation, mental quality training, attention maintenance training, etc. In addition, there are also applications in special fields such as police, military, pilots, prison personnel and other high stress people’s physical and mental health maintenance. Third, the operation technology of biofeedback therapy 1, electroencephalography (EEG) feedback varies according to the brain waves (1) δ wave (0.5-4HZ): the background rhythm of the newborn is dominated by δ wave, normal adults only in the sleep state will appear δ wave, such as in the waking state, the discharge site may have lesions, such as epilepsy, traumatic brain injury, etc.. (2) Theta wave (4-8HZ): it is related to sleep and creative thinking. Through the enhancement training of theta wave, the proportion of theta wave in EEG can be increased to treat insomnia and sleep disorders, neurasthenia, etc. (3) Alpha wave (8-13HZ): It is most obvious in the parietal and occipital areas of the head and is related to deep thinking. When a person is thinking deeply about a problem, the body is in a highly relaxed state. Therefore, doing alpha wave enhancement training in anxiety treatment to increase the proportion of alpha waves in EEG can improve anxiety symptoms. (4) SMR rhythm (12-15HZ): It is related to the self-control and regulation ability of the muscle body. (5) Beta wave (16-30HZ): related to human attention and anxiety. When the EEG is dominated by beta waves, people will only be in two states: non-fight or flight. Doing beta wave enhancement training can improve the individual’s level of alertness and improve the attention deficit problem. 2, electromyography (EMG) feedback: is a more common biofeedback technology. The degree of muscle tension is positively correlated with the degree of emotion, and the skeletal muscle in the forehead is the most representative. Used for the treatment of various tension, insomnia, anxiety states, as well as certain psychosomatic diseases, but also for the rehabilitation of paralyzed patients. For anxiety, tension and insomnia, relaxation training is generally done to inhibit myoelectricity, while for the rehabilitation of paralyzed patients, myoelectricity enhancement training is done to allow the patient to gradually regain consciousness. 3, skin temperature (TEMP) feedback: the contraction and diastole of peripheral blood vessels determine the change of skin temperature. The change of skin temperature at the fingertip (ventral side of the little finger) is recorded by a thermosensitive varicose resistive thermometer and converted into acoustic, optical and digital signals for feedback to the patient for training so that he can learn to control the degree of peripheral vasodilation. It is used to treat neurovascular dysfunction, such as migraine and Raynaud’s disease. Skin temperature can also be considered as an indicator related to relaxation and is used for relaxation training. 4, skin electrical (SC) feedback: when a person’s sympathetic nerve excitement, sweat gland secretion is enhanced, the level of electrical conductivity is increased, so the skin electrical response and emotional excitement is closely related. Record the skin electrical response signal, mainly to measure changes in skin surface resistance, and convert it into audio-visual signals for patients to carry out emotional control training. It is mainly used to treat anxiety, phobia, hypertension, asthma, and hyperhidrosis. Relaxation training is mainly done to inhibit skin electricity. 5, blood volume (BVP) and electrocardiographic (EKG) feedback: mainly used for patients with primary hypertension, but also for other cardiovascular symptoms, such as arrhythmias. 6, respiratory (RESP) feedback: mainly used for relaxation training, combined with electromyography as an auxiliary means, requiring the trainee to do deep, slow and steady breathing, feedback requirements to reduce the respiratory rate and enhance the respiratory amplitude. Fourth, the considerations of biofeedback therapy Before treatment, the therapist and the person being treated should trust each other, eliminate misunderstandings, form a consensus on biofeedback therapy, and establish a good therapeutic relationship. The patient should be released from physical and mental restraint, evacuate urine and stool, and properly dispose of belongings. During the treatment, the treated person should relax the body, breathe calmly, concentrate mentally, reduce distractions, and enter into a state of complete physical and mental rest. At the end of the treatment, the therapist will discuss the treatment experience with the participant, affirm the achievement, and encourage him/her to make continuous progress in future training.