Individuals and some healthcare professionals typically use a biofeedback system to monitor and consciously regulate many of the body’s automatic functions. The functions that may be regulated through biofeedback include heart rate, blood pressure, sweat gland activity, body temperature, and muscle tension. By consciously controlling the body’s automatic processes, individuals may be able to reduce the physical effects of stress or relieve some symptoms of certain disorders.
Biofeedback systems are purported to alert a patient or individual to potential problems in his or her body that may not normally be noticeable. These systems typically use special sensors, such as electrodes or thermometers, to detect the automatic processes at work. This equipment may alert the individual of changes or happenings by some sensory cue, such as a flashing light or a beep. For example, a light may blink whenever a heart beats on a heart monitoring machine.
A biofeedback system may also help an individual to consciously alter the problem area, simply because he or she is aware of it. Many of these systems train people in relaxation techniques, such as deep breathing and meditation, because patients who are alerted to irregular body functions by a biofeedback system may work to alter responses. An individual who utilizes these relaxation methods while being monitored by the machine may be able both to track and to promote positive change to the problem area.
There are many types of machines used in biofeedback therapy, and each biofeedback system typically targets a different set of stress indicators. An example of this is the electromyograph (EMG). An EMG senses muscle tension using electrodes that detect the level of muscle activity. Many biofeedback practitioners use EMGs to detect tension in facial, neck, or shoulder muscles which may indicate stress. Others may use EMG in biofeedback therapy to assist people with paralysis, migraines, and cluster headaches.
A feedback thermometer is another type of biofeedback machine. It detects changes in the skin’s temperature, typically in the fingers or feet. A drop in temperature at these areas may be associated with an increased level of stress because blood is diverted to the muscles and internal organs. This system may also be helpful in treating circulatory diseases, such as Raynaud's disease.
An electrodermal response (EDR) indicator is another piece of biofeedback equipment. This machine measures the productivity of the sweat glands by detecting changes in the electrical conductivity of the skin, or dermis. Periods of stress or high emotion are often accompanied by an increase in sweat. This biofeedback system is often useful for treating anxiety, phobias, and even stress-induced stuttering.
Another major type of biofeedback machine is the electroencephalograph (EEG). This device focuses on changes in brainwaves. With it, the patient is alerted to what brainwaves are working during different states of alertness from wakefulness to deep sleep. Such a system may help the patient promote desired changes in his or her brainwaves at a given time, like helping a person suffering from insomnia to increase the brainwaves present during sleep.
