Pixel Watch: Explained: How Google is using AI, multiple sensors to improve heart rate tracking in Pixel Watch 2

Google launched pixel clock 2 smartwatch with its latest smartphone lineup, the Pixel 8 series. This is the first smartwatch from the tech giant to be made available in India. Google’s Pixel Watch 2 comes with several health-related features like heart rate tracking, SpO2 monitoring, sleep tracking, and Fitbit Integration. The company has now updated its blog post to explain how it is using AI to improve heart rate tracking On the latest wearables.
The company points out that tracking important health metrics like sleep and stress wouldn’t be possible without heart rate tracking. decarlos loveA wearable product manager that works google pixel watch And Fitbit devices said heart rate tracking is “really the foundation of a lot of things.”
How heart rate tracking works on Pixel Watch 2
Google Pixel Watch 2 is equipped with photoplethysmography (PPG) sensor that uses light to measure the amount and speed of your blood circulation. The sensor works by shining a green LED light on the user’s wrist, which then reflects blood movement back to the sensor.
To compare, the original Pixel Watch had a single-path PPG sensor, while the new Pixel Watch 2 has a new multi-path LED sensor. decarlos Explains that having multiple LEDs and a photodiode (a device that detects the amount of light reflected from blood) helps the watch cover more surface area on the user’s skin. This helps the wearable provide more accurate recordings when all sensors are activated.
The lights will also operate depending on the mode selected by the user. Passive all-day tracking helps extend the Pixel Watch 2’s battery life, while Exercise mode – which turns on all sensor lights – can capture more accurate heart rate data when users are moving faster. , such as during HIIT work out.
How Google uses AI to improve heart rate tracking
For Pixel Watch 2, Google has also developed an improved algorithm which is powered by AI. DeCarlos highlighted: “These new devices capture more data related to heart rate. And now we can give it to these advanced algorithms – because AI algorithms are good at knowing what to do with even more data.

DeCarlos also explained how these algorithms have evolved. He said: “When we first started working on it, I would do things like go outside and run on the beach to try and break the algorithm – I wanted to try activities that it didn’t see. or wanted to do things that would suddenly increase my heart rate so we could validate against different scenarios.”
Google claims that the heart rate team not only trained the algorithm on a variety of activities, but also considered a number of factors when doing so, including skin tone, age, gender, and different lighting environments.
The HR sensor and improved AI-based algorithms enable the Pixel Watch 2 to give users a daily readiness score. This score tells users if they’re ready for a tough workout, if they need a rest, or if they can pick up a little pace. It all starts with getting an accurate reading of the user’s heart rate.