What is a Biofeedback Instrument?

A biofeedback instrument is a device that uses sensors to measure a signal from the body related to your nervous system that then shows you the information as it is being measured.  It is different than getting your blood pressure checked or taking your pulse and getting one reading for one moment in time.  The measurement and feedback of information are continuous.

This information can be used for monitoring and might not even be shown to the person that it is being measured from.  This is sometimes done in research.  Let’s say a researcher wants to find out how a person’s body reacts to watching a scary movie or counting backward by 7’s. They could attach sensors to a subject and monitor signals like heart rate or sweat activity to acquire a measurement related to the physiological reaction of the stimulus.  When used in this way it would be more accurate to refer to the process as physiological monitoring instead of biofeedback.

Biofeedback instruments are also used in certain types of therapy for things like pain and stress management or to improve attention or performance.  When they are used for these applications the person from who the sensors are measuring needs to be able to get visual or auditory feedback indicating the changes that are happening.  If the signal goes higher or lower the person gets a visual signal on the instrument or a computer that it may be connected to and or a sound that indicates the change.  With this information and some coaching from a therapist, the person can learn to change the signal.  They can learn to increase or decrease it using their mind.

What kind of signals can be measured from the body?

Surface EMG (Electromyography) – Action potentials produced when muscles contract.

Skin Temperature – Temperature increases when blood vessels dilate with relaxation and decreases when blood vessels constrict in response to stress.

Skin Conductance – Increases when sweat increases on the hands in response to emotional reaction.

Heart Rate and Heart Rate Variability – Changes with changes in the autonomic nervous system.  It is related to vagal tone and can be affected by emotional state and breathing as well as physical activity

Respiration – Measures depth and rate of breathing.

Capnometer – Measures the amount of CO2 in the air that is exhaled through the nostrils into two tubes connected to an instrument.

EEG (Electroencephalograph) – Measures action potentials produced when neurons in the brain fire as part of their communication and function.

These are the most common signals that are measured with biofeedback instruments.  There are various manufacturers and models.  Some are self-contained, some interface with personal computers, and some work with smartphones and tablets.  Some are intended for professional use in a licensed health care office and others are designed to be used at home by non-professionals.

I hope that you now have a basic understanding of what a biofeedback instrument is and what it is used for.  Feel free to comment or ask questions.

Harry L. Campbell

914-762-4646 – Harry@biofeedbackinternational.com

Author of What Stress Can Do, Available on Amazon.com

Biofeedback Resources International Corp.