Using smart lighting to help maintain a healthy sleep schedule

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I recently implemented a smart lighting system in my apartment in order to help maintain a consistent and healthy sleep schedule. From what I’ve read, light has a significant impact on our bodies’ circadian rhythms. Exposure to light (especially blue light) suppresses the release of the sleep hormone melatonin, and consequently, keeps you awake. Here is an excerpt from an article from Harvard Medical School describing this:

While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours).1

Based on what I’ve read, it seems best to avoid blue light for a few hours prior to bedtime in order to promote the release of melatonin. Prior to the invention of electric light, there probably weren’t many particularly blue sources of light at night time (fires, lanterns, and the like all strike me as having a more yellow-ish hue). But, we live in the age of electronics, and have device screens to contend with; The same Harvard Medical School article says that “the proliferation of electronics with screens, as well as energy-efficient lighting, is increasing our exposure to blue wavelengths, especially after sundown.” With that in mind, in addition to this lighting system, I have made a point of avoiding screens after a certain time of day (I’ve chosen 9:00pm as the start of no-screen time). I have also made a point of not drinking caffeine after 1pm in order to help with falling asleep at night, since on average it takes the body about 5 hours to eliminate half the caffeine from your system2, and I want to minimize the impact of my caffeine intake on my sleep.

So, conceptually, that’s the idea behind my implementation of this smart lighting system: to use a blue-ish white light in my apartment during the day, and a yellow-ish white light during the evening, in order to promote the release of melatonin before going to sleep. Additionally, the lights come on and fade out at the same time everyday, further reinforcing my daily sleep schedule. I implemented this arrangement using the Philips Hue lighting system, using their White Ambience bulbs, which have been created for the purpose of offering both blue and yellow tints of white light. The system is comprised of special lightbulbs which connect wirelessly to a central hub via bluetooth, and the hub connects to your router via an ethernet cable. Using this setup, you can then program and control the lights from the Philips Hue app on your phone. They also offer additional hardware peripherals for controlling the lights: I purchased the Hue Dimmer Switch and a motion sensor.

After replacing the normal bulbs in the light fixtures of my apartment with Philips Hue bulbs, I created schedules for the lighting events I wanted, and specified what I wanted to have happen when the buttons on the dimmer switch were pushed, and when the motion sensor was triggered. I connected the main ceiling lights in my apartment to the Hue Dimmer Switch, which allows me to turn them on and off, and select the lighting preset I want (e.g., an energizing blue white, a relaxing yellow white, or a dimly-lit nightlight). The dimmer switch works well enough, and is generally my main touchpoint for the system. Having a tactile switch is satisfying and familiar, and allows me a straightforward way to easily control the main lights in my apartment without having to use my phone. I connected the bathroom lightbulb to the motion sensor, so it comes on automatically when I walk into the bathroom. The biggest thing I had to get used to with this new system was not using the wall light switches in my apartment. To use the system correctly, I had to do everything through Philips’ peripherals, or through their smartphone app, so I had to break the habit of turning light switches on and off. But, not that big a deal, it hasn’t been that hard to get used to.

I did encounter a few small annoyances in my effort to get the system to work the way I wanted it to, but nothing that was a real deal-breaker. Here are the issues I encountered:

  1. If the lights are off, but you have a “routine” set up to transition the light from one colour to another, the lights come back on when the routine begins. For my purposes, I wanted the routine to transition the lights from one colour to another at that time of day, but not turn the lights back on if they were already off in order to make the transition. Additionally, it would be nice to be able to have the lights automatically come on as the appropriate colour temperature for a particular time of day when you turn the lights on. But, that functionality doesn’t appear to be there by default, and I didn’t find any third party apps (or Philips “Labs” apps) that did this well. I also didn’t see a way of setting a conditional for the routines in the Philips app, such as “only run this routine if the lights are already on.” I have gotten around this issue by just selecting the colour of light I want from the Hue dimmer switch I have when I come home. In the morning it’s set to come on as blue-ish white. I still have one colour transition routine at 8:30pm, to transition from blue to yellow, and the lights will indeed turn back on to make the transition, even if I’m not home. I haven’t found a way around this with the official Philips Hue app, but I’m typically home at that time, so it hasn’t been an issue.
  2. I didn’t have much luck using geo-tracking (of my phone) to turn the lights off automatically when I leave my apartment. I couldn’t find a way to set the geo-tracking bounding box in the official Philips Hue app, it seems to have a default bounding box. I tried using this a few times, and when I came back home the lights were still on. A lot of the places I go aren’t far from my apartment, and I suppose some of them aren’t far enough away to trigger the geo-tracking to turn the lights off. So, I gave up on this feature, and I just turn the lights off with the Hue dimmer switch when I leave, same as one would with a normal light switch.
  3. The motion sensor only lets you specify lighting for two different periods of time (i.e., day time and night time). Ideally, I would like to be able to specify three or more: Day time (blue-white), evening (yellow-white), and night time (nightlight).

These issues might be resolvable by doing more customization using third-party apps, but that would be something I would have to spend more time looking into later down the road. So far, the system seems to be helpful with maintaining a better sleep schedule. I do indeed seem to become more sleepy around bedtime, and have been having less trouble falling asleep. The lights act as a visual reminder that help keep me on a consistent schedule and routine, and I have a hunch that this may be helping me maintain a consistent schedule with other things beyond just sleep (e.g., eating meals at the same times each day). On the whole, I am satisfied with how the system is working out.

 

References:

1. Harvard Health Letter. Blue light has a dark side. https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side. Accessed September 4, 2017.

2. Institute of Medicine (US) Committee on Military Nutrition Research. Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. Washington (DC): National Academies Press (US); 2001. 2, Pharmacology of Caffeine. Available from: https://www.ncbi.nlm.nih.gov/books/NBK223808/