The techniques used to teach biofeedback depend upon individual patients’ health problems and what they wish to accomplish. Methods and equipment that may be used include:

• Electromyography (EMG). Sensors (e.g., electrodes) are attached to the skin to measure the electrical activity of the muscles. This activity relates to muscle tension, which can influence or cause pain and stress. The patient learns to recognize tension early and control it right away.
  
  
• Neurofeedback. An electroencephalogram (EEG) is used to monitor brain-wave activity and teach patients to alter it. This activity may be linked to different mental states, such as wakefulness, relaxation, calmness and light or deep sleep.
  
  
• Thermal biofeedback. Sensors are attached to the patient’s fingers and feet to measure skin temperatures. These temperatures often drop when the patient is under stress, so a low reading can prompt the beginning of relaxation techniques.
  
  
• Galvanic skin response training. Sensors measure perspiration and sweat-gland activity. This method is useful in the treatment of emotional disorders (e.g., anxiety, phobias).
  
  
• Forced oscillation method. The patient breathes through a tube and pressure and flow of the breath are assessed using a device called a pneumotachometer. This method teaches control of respiration.
  
  
• Bowel training. A pressure-sensitive probe is inserted into the anus and rectum to register the strength and activity of the anal sphincter. This training allows patients to practice sphincter contractions and to learn to strengthen the rectal muscles.