Google has added fall detection to its Pixel Watch.

Fall detection uses motion sensors built into the watch and on-device machine learning to determine if the wearer has taken a hard fall; it will call emergency services if they do not move or respond within a certain time.

The feature can be turned on in the Updates page on the Watch Companion app or directly on the Pixel Watch in the Personal Safety app.

If the wearer takes a hard fall and the watch detects they aren’t moving for about 30 seconds, it will vibrate, sound an alarm and display an on-screen notification. If they are able, they can either tap “I’m OK” on the watch face to dismiss the notification or tap “I fell and need help” to be connected to emergency services right away.

Otherwise, the alarm will continue for about a minute, getting louder in the final few seconds. If they still haven’t responded, the watch will automatically attempt to call emergency services and play an automated message that requests help to wherever they are. Wearers can also speak to the emergency operator themselves, if possible, to let them know whether or not they need help.

The Pixel Watch knows the difference between taking a hard fall and performing a vigorous physical activity or even quickly recovering from a small stumble thanks to machine-learning algorithms and rigorous testing. The motion sensors and algorithms can monitor for a sudden impact and the body’s responses and instinctive reactions to falling.

“We trained this process using a broad variety of human and simulated fall data and other motion patterns to accurately detect real falls and minimise potential false alarms,” said Paras Unadkat, product manager for Pixel Watch. “We also tested this feature against high-energy activities that involved impact, sudden drop or excessive arm movements – think activities like burpees, jumping or swimming – to avoid those types of activities from triggering a false notification. And we worked with emergency dispatch services to test that calls were smoothly connected and the automated messages were as helpful as possible for everyone involved.”

When a user sets up fall detection, they will also have the option to toggle on a setting called “Help improve fall detection”, where Google may collect the motion sensor data of events detected as falls to make future improvements for this feature. Users can also turn off fall detection at any time if they no longer want the feature enabled.

The Personal Safety app on Pixel phones also includes car crash detection and emergency broadcast notifications. Additionally, Emergency SOS on the Pixel Watch alerts emergency responders or trusted contacts when the wearer is in an emergency or feeling unsafe.