Circadian-based smart sleep mask

As I struggled with my sleep freshman year of college, I got interested in making a better alarm clock. As it turned out, my friend Aiden had been in a similar boat in high school, and had a similar interest. He'd been working on a smart sleep mask idea for a while, and after talking about it, we started this project.

The core idea of Circadian, as we dubbed our mask, is that the human biological clock can be manipulated with artificial light. This causes problems when we stay up late on computers, but it turns out, can also be helpful if you time your light properly. Beyond just giving your body light exposure when you want to feel awake, a number of studies have shown that light exposure while asleep can drastically adjust your circadian rhythm.

Interested by this, Aiden and I read a few dozen papers, and started making mask prototypes. I designed the housings, programmed the app, and wrote the firmware for the mask while Aiden handled the custom electronics. We've produced a few dozen prototypes for better comfort and fit and are now on our third generation of the app.

The mask works by outputting light pulses at specific times based on your sleep schedule according to an algorithm in the app. The algorithm calculates estimates of your body's schedule using your sleep patterns and self-reported data. The app then talks to the mask via BLE, leaving it to stay in deep sleep 99% of the time.

This was my first time using SwiftUI, and I've had a lot of fun working on the app. Currently, we're shipping masks to a few early customers that found us online, and I'm updating the app to support more alarm features now that AlarmKit is available.

As it stands today, I've used the mask for a few months (totaling thousands of hours), and have seen long-term improvements in my average nightly sleep onset this semester compared to the same time last year.