Apple is working on a smart ring that can detect gestures and track objects in a user's hand, according to a leaked patent.

The patent, uncovered by Apple Insider, shows a ring designed to connect to other devices and tell them exactly where the hand is located. While still a patent, this is exactly the kind of thing that could be used in Apple's VR or Mixed Reality headsets, or Apple Glasses.

The patent also includes a "Self-Mixing Interferometry-Based Gesture Input System Including a Wearable or Handheld Device It is catchily titled "Self-Mixing Interferometry-Based Gesture Input System Including a Wearable or Handheld Device," which is broad enough to cover any wearable device. For the most part, however, the focus is on the use of this "Apple Ring."

The idea is that the ring contains a self-mixing interferometry (SMI) sensor that can be used to detect what your hands are doing.

It does this using "one or more beams of electromagnetic radiation" in different directions, which are then used to draw a digital image of what is in the immediate vicinity.

A number of SMI sensors would give the ring additional capabilities. For example, one sensor could track the movement of the ring and the user's hand, but two or more would allow a wider range of motion to be detected. Similarly, multiple rings would have the same effect.

The exact process is vague, but one example is a user wearing a ring while using the Apple Pencil. The ring detects the movement of the stylus, allowing the user to write or draw in the air.

When it comes to Apple's nascent augmented reality efforts, it is clear that this type of device would be invaluable.

Apple's VR and mixed reality headset will reportedly include about 15 external cameras for a variety of uses, including tracking the user's arms and fingers. However, it is unclear how accurate that system will be, and a set of wearable rings may help the headset keep track of user activity.

The Apple Glass AR glasses may be too small to accommodate many cameras and sensors, but if realized, they could benefit from the new technology. Unfortunately, the patent does not elaborate on how other devices could take advantage of the SMI-based gesture input system.

There is no guarantee that the patent will necessarily be commercialized or that these rings will be released. But it is another sign that Apple plans to move further into the realm of VR and augmented reality.