In 2017, Apple acquired Beddit - a company which creates devices to keep track of the sleeping schedule.
A year after buying Beddit, Apple took out a patent for a device that tracks a person’s sleep.
Apple filed an application for a patent on May 22, and six months later it was published on the website of the United States Patent and Trademark Office. Most sleep sensors are designed in such a way that a person should put it on. But Apple decided to take a different tack and developed a multi-element piezo sensor for in-bed physiological measurements.
Apple engineers have created two versions of the piezo sensor. The first, in the form of a Beddit sensor, is a thin strip that crosses the bed roughly where the chest of the user is positioned. The second option includes a wider range of sensors that cover the entire bed. This piezo sensor can track the body position more accurately.
According to the application, the piezo sensor can be corrugated to create more sensitive contact zones.
We can't say for sure whether this patent has something to do with the fact that Apple is now the owner of Beddit, but the concept of the first version resembles the one employed in the Beddit 3 sensor system, which is sold in the online Apple store. It is also worth considering that not all Apple patents are transferred to finished products.