Description of Biofeedback Modalities:

Psychophysiological Stress Profile: The PPSP is an assessment of physiological response during stress.  A baseline measurement is obtained with respiration, sEMG, GSR, skin temperature and/or heart rate.  (Other modalities may also be used) 

Skin/Surface EMG (sEMG):  Is a measure of the electrical activity produced by muscle groups   It is reflective of the client’s level of tension and motor control over a muscle or region.  Ideally the muscle should both relax and contract quickly and efficiently.   A baseline is established at each session. 

Basal Skin Response (GSR, Skin conductance):  is a phasic measure of electrical resistance in the epidermis and is measured in ohms.  This resistance is created by autonomic activity in the eccrine sweat glands, which is easily measured on the fingers.  In general, the higher the reading, the lower the sympathetic activity or arousal taking place.  “Higher is drier” with this measure. 

Heart Rate (HR): is measured using a photoplythsmograph (PPG) and should be variable.  In general, we should see an increase in HR as the client inhales and a decrease as the client exhales.  This is known as normal respiratory sinus arrhythmia (RSA).  It is a reflection of the sympathetic and parasympathetic nervous systems correct signals to the sino-artrial node in the heart.  Working with the RSA pattern, we generalize the readings to sympathetic and parasympathetic activity throughout the body.

Heart Rate Variability (HRV): is a measure of heart rate using a Fourier Transform analysis to generate spectral display from the raw PPG tracing.  It reflects sympathetic and parasympathetic influences on the heart.  When the influences on the heart are balanced, a spike appears around the .1Hz area of the spectrum.

Blood Volume Pulse (BVP): is extracted from the raw data present in the PPG tracing. It is an indirect measure of blood pressure and blood flow.  As the signal increases we can extrapolate that the blood pressure is dropping.

Skin Temperature: is a measure of surface skin temperature and is measured on the fingers and/or toes.  Skin temperature is related to vasodilatation and vasoconstriction. It is a measure of sympathetic or arousal activation or deactivation.

Respiration:  is a measure using a strain gauge positioned across the abdomen and/or chest.  Diaphragmatic breathing is encouraged, depending on the client’s medical history and capnometry readings.  Limited amount of upper chest and trapezius movement is encouraged. However, the emphasis is on effortless breathing.  Signs of hyperventilation and over-breathing are monitored and clients are educated regarding these breathing problems.  Diaphragmatic breathing decreases arousal and is very helpful for any condition exacerbated by stress, anxiety and pain.