Biofeedback was founded by Elmer and Alyce Green of the Menninger Institute in Topeka, Kansas. It's been successfully used in many research centers throughout the world. The technique teaches patients to consciously control bodily functions that were previously thought to be controled only through the subconscious mind.
Some of the techniques use a biofeedback device by placing sensors on the skin to measure skin temperature, brain function and nerve action. The signals are amplified and shown on a dial for a patient to observe. With focus and concentration, the pateint can change the reading and discovers that he is not entirely controlled by outside forces. In accomplishing this task, he can learn to minimize stress which is often the cause of many other maladies. As the person learns to control their bodily functions, they teach themselves how to control and cope with problems in every day life.
Back when biofeedback was founded, it required expensive equipment and training by professionals. However, with the advancement of technology in our day and age, there are plenty of sources where people can purchase and build their own biofeedback devices and train themselves with a bit of effort. The extraordinary thing is how its been used to eliminate things like psychosomatic illnesses, asthma, skin problems and migrain headaches.