Physiological Effects of Blue Pulsed LED in an Indoor Lighting Environment

Abstract

Purpose: An experiment was conducted to investigate the physiological effects of a continuous blue pulsed light emitting diode (BP-LED) added to a task lamp in an actual indoor lighting environment and its influence in alertness having as a final purpose to develop a commercial product that could be applied in situations similar to those depicted in the present work. Design methodology: Previous research studies have stated that the addition of pulsed light evokes physiological changes that may induce alertness. The participants were exposed to four different lighting conditions. Electroencephalograms (EEG), pupil sizes, heart rates (HR), performance tests, and subjective reactions were measured. Findings: Low colour temperature light and the BP-LED revealed an improved alertness according to the data from the EEG recordings. The intervention of the BP-LED in a high colour temperature ambiance was beneficial in maintaining high levels of alertness compared to the conditions where the BP-LED was not used. It was tested that the use of a BP-LED in a task lamp may be beneficial in improving or maintaining alertness levels in an indoor workplace ambiance. Originality and Value: Designing of an adequate workplace task lamp light that improves alertness for in-house, office, or classroom situations in which it is essential.

Physiological Effects of Pulsed LED Light Added to a Task Lamp to Improve Alertness on Employees of Hospital or Shift Workers

“…This study supports the previous finding that BP LED helps to improve the state of alertness [10] and therefore it can be applied in what was proposed by adding the continuous pulsed LED light to a task lamp in order to In regards to the subadditivity response, could be a good reference as a future step to measure pulsed…”

“…In a parallel study from a joint research, the mixing of short pulses (100 μs) of blue light with a white light background, was observed an increase in pupillary constriction due to the blue light intervention although blue color was not perceived by the participants in a way that they could continue their work without feeling that the workplace surface or area was changed to a bluish tonality [10] [24] . This type of result show that blue can be added to general illumination as long as it is not perceived by human eye, the effect can be delivered without affecting perception and may allow worker to maintain a high arousal level as the one needed in Hospitals, Schools or an Office setting.…”

“…Exposure to pulsed light results in non-visual physiological responses in humans [1] [9] . The present study aims to investigate whether such non-visual effects are influenced to a greater extent by the frequency of flickering or by the combination of colours of lighting, this research obeys to a previous experiment in which an intervention of Blue Pulsed LED was used as an addition to a task lamp in order to improve the state of alertness in humans when a continuous stream of pulses at 100 Hz was delivered to a conventional workspace [10] . The actual study was developed in order to find the electroencephalogram (EEG) behaviour to determine differences among flickering frequencies in order to determine which one evokes the most and apply it to a prototype desk lamp.…”