Stress research- Light justification

We wanted to incorporate some features into our design that would help create increase and improve the calming sensations and relieve stress. when researching into the ideas behind stress we found breathing to be a major contributor to relieving stress and a sign of some one who is stressed.
according to Harris, Katkin, Lick and Habberfield breathing controlled at a calm, steady pace and is inhaling for 4 seconds and exhaling for 4 seconds helps calm and relax people and will have a positive effect on ones mindset.
We decided we could use this technique inside the pod through the use of a light.
Inside the pod a light at each end will fade on and off at 4 second intervals creating a smooth harmonious light in which the user will respond positively to, and breathing will automatically relax and follow the pattern of the light, creating a less stressful and relaxing environment, perfect for the relaxation pod.
We looked at either having a rim of small lights, or big lights and placements. We decided against a lot of lights and small lights, as it could end up creating a rave like atmosphere. instead we have settled on one or two, big lights, placed either at the head and foot of the pod, or one placed in the middle on the side.