Apple's first patent for 'Fall Detection' was published in 2018 under application 20190103007. Since that time we've posted a couple of related patent reports on the subject (01 & 02) with the former including "crash detection." Today the U.S. Patent and Trademark Office officially granted Apple a more detailed patent regarding Fall Detection.

In one aspect, Apple's granted patent covers a method that includes obtaining, by a mobile device (Apple Watch), motion data indicating motion measured by a motion sensor over a time period. The motion sensor is worn or carried by a user. The method also includes determining, by the mobile device, an impact experienced by the user based on the motion data, the impact occurring during a first interval of the time period.

The method also includes determining, by the mobile device based on the motion data, one or more first motion characteristics of the user during a second interval of the time period. The second interval occurs prior to the first interval. The method also includes determining, by the mobile device based on the motion data, one or more second motion characteristics of the user during a third interval of the time period. The third interval occurs after the first interval. The method also includes determining, by the mobile device, that the user has fallen based on the impact, the one or more first motion characteristics of the user, and the one or more second motion characteristics of the user, and responsive to determining that the user has fallen, generating, by the mobile device, a notification indicating that the user has fallen.

Apple's patent FIG. 2A below is a diagram showing an example position of a mobile device on a user's body; FIG. 2B is a diagram showing example directional axes with respect a mobile device; FIG. 12 is a diagram of an example state machine for determining whether to transmit a distress call using a mobile device.

Apple's patent FIG. 20 below is a schematic representation of an example fall state machine; FIG. 21 is a diagram of different types of falls that may be experienced by a user.

For more details, definitely review Apple's granted patent 11468759. This patent is packed with details. For instance, just in the patent summary alone Apple listed 124 specific points about their invention.