Is There More to Blood Volume Pulse Than Heart Rate Variability, Respiratory Sinus Arrhythmia, and Cardiorespiratory Synchrony?

A growing body of research reports the health benefi ts of training heart rate variability (HRV), and the clinical use of HRV training protocols has increased dramatically in recent years. Many of the home training devices and many of the sophisticated biofeedback instrumentation systems rely on the blood volume pulse (BVP) sensor, or photoplethysmograph, because it is more user friendly than the electrocardiogram used in medical settings. However, the BVP signal is valuable in its own right, not merely as a convenient measure of HRV. This article explores the methodology of BVP recording, the underlying physiology, and the potential benefi ts from BVP treatment and training protocols. For example, the shape of the BVP waveform refl ects arterial changes correlated with hypertension. In addition, BVP training offers promise for the treatment of migraine and the monitoring of human sexual arousal.