Abstract:
The objectives of this research were 1) to develop a blue-light cap for
alertness stimulation in people with drowsiness, 2) to study the effects of blue light
exposure durations on alertness in conjunction with electroencephalogram and 3) to
analyze the equations between blue light duration and electroencephalogram.
Participants were 80 undergraduate students from Burapha University, academic year
2019. The research instruments consisted of Karolinska Sleepiness Scale (KSS) and Muse
electroencephalograph. Two-way ANOVA was used for analyzing the data.
The results showed that the development of a blue-light cap for alertness
stimulation required 8 blue light LEDs of 5 millimeters, 470 nm wavelength. LEDs were
installed in front of the cap at a distance of 5 cm from the eyes. They provided a
brightness of 40 lux. The device had a power supply that used 9 volt batteries.
Behavioral results showed that groups exposed to blue light at different durations had
different alertness levels (evaluated by KSS) with statistical significance at the .05 level.
Electroencephalogram results found differences of EEG power spectral density (PSD) in
groups exposed to blue light at different durations with statistical significance at the .05
level. These results were found in alpha and beta waves at the AF7 and AF8 electrode
sites, and beta/alpha ratio at the AF7 electrode site.
The determination of the equation between the blue light duration and
electroencephalogram showed that Y = -0.005X2
+ 0.023X + 0.176 was the best fitting
curve (with R
2
= 0.825), obtained from beta waves at the AF7 electrode site.