Effect of acupuncture on the autonomic nervous system as evaluated by non-contact heart rate variability measurement

We evaluated the effect of acupuncture treatment on the autonomic nervous system by measuring the non-contact heart rate variability (HRV). HRV shows the changes in sympathetic and parasympathetic nervous activities. Sympathetic and parasympathetic nervous activities are respectively reflected in the high-frequency- (HF) and low-frequency (LF) components of HRV. Many studies have shown that sensory stimulation affects the cardiovascular system. In particular, acupuncture stimulation often decreases the LF component, and there is a significant positive correlation between the HF component and the number of acupuncture sensations administered. These previous studies generally used an electrocardiograph or other contact plethysmograph to obtain the HRV. However, the use of electrodes and contact sensors might cause the participants to experience stress. Therefore, we used non-contact HRV measurement to evaluate the effect of acupuncture treatment. Using a remote measurement system with a digital camera enables the exclusion of external factors, and the attainment of more natural biological information. In the present study, we verified the accuracy of remote HRV measurement using a digital camera, and evaluated the effect of acupuncture on the autonomic nervous system.