Phones and wearable devices now collect all kinds of biometrics data, but nobody has yet figured out how to use sensors to measure body fat.

Well, Samsung may have. A new patent describes a method of using four sensors installed in or near a phone. By “near” I mean that the Samsung method might involve four sensors embedded into the screen cover of a phone case.

The four sensors work together to measure impedance levels resulting from contact with the human body. In the illustrations in the patent, a person is shown using both hands to grip the sensors.

The patent explains the technology as “acquiring the object’s impedance information on the basis of the intensify of the input current and the intensity of the measured voltage; and acquiring the object’s body fat information on the basis of the impedance information.”

It all sounds a little vague, but if the technology works it could be a boon for health and exercise apps that run on Samsung phones.

Research provided by legal technology firm SmartUp Legal