Pixel Watch 3 finally getting Loss of Pulse detection feature in the US

About six months after its initial announcement at the Made by Google event, the Pixel Watch 3 is finally getting Loss of Pulse detection feature in the US. The search giant announced that it has received approval from the US Food and Drug Administration (FDA) and starting with the Pixel Watch 3, the feature will arrive at the end of March. Loss of Pulse detection has been available in 14 countries since its announcement in 2024.

According to Google, Loss of Pulse is a first-of-its-kind feature that can detect if the heart stops beating due to a primary cardiac arrest, respiratory or circulatory failure, overdose or poisoning, and then alert the emergency services for prompt, potentially life-saving care. The feature will first ping the user and ask them if they are alright. If there is no response from the user, the emergency services will be contacted.

Loss of Pulse will be added to the already existing health and safety features that the Pixel Watch 3 has, such as Car Crash Detection, ECG app and Safety Check, Irregular Heart Rhythm Notifications, and Fall Detection. It will be an opt-in feature for Pixel Watch 3 users.

How does it work?

Loss of Pulse detection works by using the smartwatch’s sensors, signal-processing algorithms, and AI to detect loss of pulse. At first, if the Heart Rate sensor, which uses green light, does not detect a pulse, the infrared and red lights turn on to look for additional signs of a pulse. At the same time, the motion sensor tries to detect signs of movement. Using these results, the AI-based algorithm determines if there’s a loss of pulse event and triggers a check in notification. If there is no response, the watch will kick off an audio alarm and countdown. If there is still no response, it will use the phone connected to the watch (in case of non-LTE variant) to place a call to emergency services along with the location.