Biofeedback

Introduction

• The word "biofeedback" was coined in the late 1960s to describe laboratory procedures then being used to train experimental research subjects to alter brain activity, blood pressure, heart rate, and other bodily functions that normally are not controlled voluntarily.

• At the time, many scientists looked forward to the day when biofeedback would give us a major degree of control over our bodies.

• Some believed that biofeedback would one day make it possible to do away with drug treatments that often cause uncomfortable side effects in patients with high blood pressure and other serious conditions

What is Biofeedback?• Biofeedback is a type of complementary

and alternative medicine called mind-body therapy.

• Biofeedback is a treatment technique in which people are trained to improve their health by using signals from their own bodies.

Physical therapists use biofeedback to help stroke victims regain movement in paralyzed muscles.

Psychologists use it to help tense and anxious clients learn to relax.

Specialists in many different fields use biofeedback to help their patients cope with pain.

Biofeedback uses today

• Clinical biofeedback techniques that grew out of the early laboratory procedures are now widely used to treat an ever-lengthening list of conditions. These include:

Migraine headaches, tension headaches, and many other types of pain.

High blood pressure and its opposite, low blood pressure.

Irregular heartbeats. Epilepsy.

How Biofeedback Works • Scientists can’t yet explain how biofeedback works.

• Most patients who benefit from biofeedback are trained to relax and modify their behavior.

• Most scientists believe that :

– a key component in biofeedback treatment of many disorders, particularly those brought on or made worse by stress.

– Their reasoning is based on what is known about the effects of stress on the body.

Start here

Electrodes & Signal Processing

• The principles of EMG biofeedback (EMGBF) are usefully reviewed, as a reasonable understanding of what the machine is doing will assist the therapist in determining the most appropriate machine settings and applications.

EMG Biofeedback

• The electrodes are Silver/Silver Chloride construction which are efficient at detecting small biological electrical signals from the body surface.

• The signal is amplified, and usually filtered and then processed.

• Then it is shown on the EMG display.

Electrode Placement• Wide electrode spacing will

increase the volume of tissue from which the signals are collected, and will therefore increase the number of muscles which will influence the displayed data and conversely.

• Narrower spacing will reduce the tissue which influences the signal, making it more specific.

• Even with close spacing over superficial muscles, it is not possible to be sure that the signals are only derived from a particular muscle.

Features of the EMG Devices• Gain settings :

All biofeedback devices offer an adjustable gain setting which affects the basic sensitivity of the machine.

On low gain settings the machine will require a greater signal before the output changes ( less sensitive ).

On high gain settings, small muscle flickers will produce a large response, and this is especially useful for very weak muscles.

• Sound : Most EMG biofeedback devices offer an audible

feedback in addition to the visual information.

• Peak Hold facility : Some devices offer a peak hold facility which

enables either the signal to be fed back on a continuous basis (Peak Hold OFF) or by providing the peak signal over a slower time frame.

Peak Hold ON, the display does not change instantly, but reports the peak activity in the previous 3 second recording period.

Types of biofeedback

• Electromyogram (EMG).

• Temperature biofeedback.

• Galvanic skin response training.

• Electroencephalogram (EEG).

Results of biofeedback• Biofeedback may enable

you to reduce the amount of medication you take, or even help a condition that hasn't responded well to medication.

• To control your involuntary body functions, biofeedback may improve your medical condition and teach you valuable techniques for living a healthier life.

Should You Try Biofeedback?• If you think you might benefit

from biofeedback training, you should discuss it with your physician or other health care professional, who may wish to conduct tests to make certain that your condition does not require conventional medical treatment first.

• Responsible biofeedback therapists will not treat you for headaches, hypertension, or most disorders until you have had a thorough physical examination. Some require neurological tests as well.

Risks of biofeedback

• Biofeedback is generally considered safe. It should generally not be used, however, if you have depression, or another major mental health disorder.

• Biofeedback can potentially interfere with some medications, such as insulin, so patients with diabetes should exercise extra caution.

• Talk to your doctor to see whether biofeedback therapy is an appropriate treatment for you.

references

• www.answers.com

• www.umm.edu

• www.biofeedback.net