Apple wants to let you know when it’s time to buy your next pair of shoes.

In a recently published patent application, the tech giant has proposed embedding sensors in footwear that would track the wearer’s activity and send a notification when it’s time for a new pair. The application describes a “Shoe wear-out sensor, body-bar sensing system, unitless activity assessment and associated methods.”

The application’s summary describes the system thus:

  A body bar sensing system for sensing movement of a body bar may be provided. The body bar sensing system may include a housing having a coupling mechanism operative to couple to the body bar, a detector disposed within the housing and operative to sense movement of the body bar when the housing is coupled to the body bar, and a processor operative to determine a number of repetitions of the movement based on the sensed movement.

The summary describes a variety scenarios for the device:

In one embodiment, a shoe wear out sensor includes at least one detector for sensing a physical metric that changes as a shoe wears out, a processor configured to process the physical metric, over time, to determine if the shoe is worn out, and an alarm for informing a user of the shoe when the sole is worn out.

 The application also suggests the sensor could have practical applications besides letting the owner know when it’s time for a new pair, including helping to measure a child’s daily activity or to determine whether an injured leg is getting the proper amount of activity to facilitate recovery.

Source: CNET