Objective: We conducted a clinical study to investigate the effects of newly developed LED lighting on living comfort in an indoor environment.
Design: Twenty healthy subjects participated in a randomized crossover trial. They performed a mental task for 4 hours under ordinary lighting, and then rested for 1 hour under newly developed lighting or ordinary lighting. Sixteen of the subjects (8 males, 8 females) completed the trial. We evaluated subjective comfort using a visual analogue scale (VAS) and measured autonomic nervous system effects by the frequency analysis of a-a intervals on accelerated plethysmography (APG) waves.
Result: The subjects’ VAS evaluations showed that the newly developed lighting increased their comfort, while frequency analysis of APG during the rest period was found to activate the parasympathetic nerve system.
Conclusion: This newly developed LED lighting produces suitable illumination and color temperature and is useful for improving living comfort in an indoor environment during a rest period after daytime work.

Objective: We conducted a clinical study to investigate the effects of newly developed LED lighting on living comfort and work performance in an indoor environment.
Design: Sixteen healthy subjects participated in a randomized crossover trial. They performed a mental task (2-back task and ATMT) for 8 hours under newly developed LED lighting or ordinary LED lighting. We evaluated subjective comfort using a visual analogue scale (VAS) and work performance by ATMT. Moreover, we measured changes in the autonomic nervous system by frequency analysis of a-a intervals on accelerated plethysmography (APG) waves to elucidate the mechanism of action.
Result: The subjects’ VAS evaluations showed that the newly developed LED lighting increased their comfort and attenuated their fatigue, and ATMT evaluations showed the lighting improved work performance during the mental task period, while APG frequency analysis revealed changes in the parasympathetic nerve system.
Conclusion: This newly developed LED lighting produces suitable illumination and color temperature and is useful for improving living comfort and performance in an indoor work environment.

In the present study, we investigated the effects of plasma cluster ions on moisturizing skin and increasing comfort sensation in healthy female volunteers. Thirty-two healthy women who often experienced dry skin participated in a randomized crossover trial. We evaluated skin moisture using the Corneometer CM825 and comfort sensation using the visual analogue scale. Plasma cluster ion concentrations of 25000 pcs/cm³ increased skin moisture, while concentrations of 7000 pcs/cm³ increased comfort sensation. These results suggest that plasma cluster ions have an effect on skin moisture contents and comfort sensation.