Effect of LED light stimulation on sleep latency in night shift people

Sleep problems are getting worse and worse in modern world. They have a severe impact on psychological and physical health, as well as social performances. From our previous study, the brainwave α rhythm, θ wave and β wave were affected by radiating the palm of the subjects with low-level laser array. In addition, from other study, the LED array stimulator (LEDAS) also has the similar effects. In the present study, LED light was used to radiate the left palm of the subjects too, and the effects were assessed with the multiple sleep latency test (MSLT) and heart-rate variability (HRV) analysis. The results revealed that it doesn’t have significant meaning between these two groups. However, the tendency of the sleep latency (SL) in the LED group was shorter than that in the control group. In addition, the autonomic nervous system (ANS) analysis showed that the sympathetic nervous system was getting larger in the LED group than that in the control group, and total ANS activity were mainly getting larger in the LED group. We infer that this LED stimulation could reduce SL and balance ANS activity of the night-shift people. In the future, the further study will be conducted on normal subjects.