Effects of far-infrared radiation on heart rate variability and central manifestations in healthy subjects: a resting-fMRI study

Abstract

The aim of this study was to investigate the autonomic responses and central manifestations by peripheral FIR stimulation. Ten subjects (mean ± SD age 26.2 ± 3.52 years) received FIR stimulation at left median nerve territory for 40 min. Electrocardiograph was continuously recorded and heart rate variability (HRV) were analyzed. By using a 3 T-MRI scanner, three sessions of resting-state functional magnetic resonance images (fMRI) were acquired, namely, before (baseline-FIR), immediately after (IA-FIR) and 15 min after FIR was turned off (Post-FIR). The fractional amplitude of low-frequency (0.01-0.08 Hz) fluctuation (fALFF) of each session to evaluate the intensity of resting-brain activity in each session was analyzed. Our results showed that FIR stimulation induced significant HRV responses such as an increasing trend of nLF and LF/HF ratio, while FIR increased fALFF in right superior front gyrus, middle frontal gyrus and decreased the resting brain activity at fusiform gyrus, extrastriae cortex, inferior temporal gyrus and middle temporal gyrus, especially 15 min after FIR was turned off. We conclude that the central manifestation and the autonomic responses are prominent during and after FIR stimulation, which provide important mechanistic explanation on human disorder treated by such energy medicine.

Far-infrared stimulation of Neiguan acupoints improves heart rate variability and ameliorate fatigue in hemodialysis patients: A randomized trial

“…The protocol was prepared following pervious report. 20,22,23 Each HD patients received the assessment of HRV before and after IFR radiation on Neiguan acupoint. The irradiated site is Neiguan acupoint in the arteriovenous tube that is not performing HD, each time for 40 minutes, three times a week, 20 to 25 cm away from the body surface, and the temperature is maintained at 38°C to 40°C.…”

“…HD patients suffered from less fatigue. 22 In this study, we conducted a randomized trial to evaluate whether FIR stimulation on Neiguan acupoint can diminish the severity of HD-mediated fatigue.…”

Crossover trial of the effects of a far-infrared heater that heats the feet with ceramic balls on autonomic nervous activity and mood states

“…Physiological effects of exposure to FIR include increased cardiac output, 7 improved flow-mediated vasodilatations, 7 reduced ankle-brachial index in patients with peripheral artery disease, 8 effects on brain activity, 2 and better sleep quality. 9 Several papers have discussed the relaxation provided by FIR heaters.…”

“…Different FIR heaters employ a variety of heating systems. Classified according to the location of the heater relative to the body, these include heaters that direct FIR rays toward the skin surface from a certain distance, 1 , 2 dry saunas and other heaters that use convection currents, 3 , 4 and heaters that surround the surface of the skin with heated ceramic balls or other materials. 5 , 6 Classified according to the range of heating, heaters can heat the entire body or only parts of the body, such as the back or lower extremities.…”

“… 10 Other studies have examined effects on the autonomic nervous activity as objective endpoints. Effects included activation of the sympathetic nervous system with 40 min of exposing the upper arms to a heater located 30 cm from the skin 2 and improved parasympathetic nervous system activity from 25 min during 40 min of exposing the legs to FIR from a distance of 20 cm from the skin. 1 …”