Food as a Wearable Insight

Back in 2018, I was introduce the the Freestyle Libra 2 and 3 device. This the time I was exploring APIs and designing with Applications like Origami and Protopie. Having access to open data and really trying to design prototypes with data end points felt like a game changer.

Since I had just started playing with open API’s my partner was seriously concerned about food and what the effect it was having on her and her body. So after listening to a lot about how was food was affecting her and shouldn’t find the solution no matter what she did. This included having a camera stuck down her thought she told me that she was going to try a better understand the how food was effecting her from the inside. As always, I was curious to see how technology could help. What came through the mail was a box, a little stand alone device and a sensor to be “connected” (inserted) in the her arm with the aim of giving her more data to understand what happening to her when she was eating her daily food.

Fast forward a couple of years and ive always kept this experience in back of my mind. I remember taking a look at the app and thinking, maybe someone should design a better be app.

With my continued interested in Wearables and Smart Devices other than Phone and Tables and having worked in the last couple of years in consumer Internet of things (IoT/Smart devices) space and having in background in designing for AI and a variety of interfaces I wanted to learn more about the industry. Let’s face it this was section of my site where I get to explore different technologies that peak my interest on how they work. So let’s get into it.

When I was introduced to these kind of devices I was shown a device like the above, a rather bulky hand held device with a sensor that via bluetooth connects and reads the data. The flash glucose monitoring system records glucose levels throughout the day and night. The FreeStyle Libre 2 system is made up of the FreeStyle Libre 2 sensor and the FreeStyle LibreLink app. The system includes a small, water-resistant sensor that you wear just under the skin on your upper arm for 14 days at a time. The sensor sends real-time glucose readings to your smartphone every minute and stores up to 8 hours of glucose readings in 15-minute intervals. It is has been designed to be water-resistant and can be worn for up to 14 days, even during activities like swimming, showering, and exercising.

After a little bit of background reading about how the device worked I decided to give it a go as well. – Nothing better than having first hand experience when using a device or service I thought. After using the device I started seeing how food was effecting my body. In so many people i’ve seen how the effects food can be hard to see. Having something on the inside giving us information was a huge step forward. I only chose to wear the device for a 2 month and after this stoped since I felt it wasn’t 100% essential to my general life but I had a lasting effect on me.

Fast forward a few years closer to the present I kept this experience with me and started seeing these devices getting more and more main stream. Such as Zoe and others, taking the work of the FreeStyle Libre 2 and 3 and pushing forward to main stream and transforming these bulky stand alone devices into an App that can be loaded on Smart phones with a NFC chip.

In the last couple of months again I started reading a lot about these devices and how they work in detail, since i’ve been working in the Wearable and Smart devices sector. I’ve had a to research all kinds of devices and how they connect using different methods such as Wifi, Bluetooth, Direct Wifi, various Google and Amazon protocols to help devices connect.

To do my background my research, I came across many videos talking about how various companies have started bring these devices to main steam, for me at this point my focus was about a reviewing or learning how Zoe or other companies are using these devices but to learn more about the technology behind these devices.


How does the Freestyle Libre sensor attach? 

  • A sensor pack (contains the actual glucose sensor that sticks to your skin)
  • A sensor applicator (applies the sensor to your skin)
  • An alcohol wipe – prepares the skin pre-application

The Freestyle Libre parts are the sensor and the reader. The sensor is the small, round device that includes a tiny, flexible wire inserted just under the skin to measure glucose levels continuously. The other component, the reader, is a handheld device that scans the sensor to display real-time glucose readings, historical data, and trends.

This is the fun part.  The filament contains an enzyme called glucose oxidase, this enzyme reacts with the interstitial fluid, converts glucose to hydrogen peroxide.  A current is then generated which is electronically transmitted to your reader or smartphone app.

For a more detailed scientific understanding on how does the sensor measure glucose  (This amazing detailed read to understand how the sensor works) here’s one of many articles that digs deeper.

It’s important to note that this is an interstitial reading not a blood reading.  It is a proxy for a blood reading.  It’s good enough for me.