Tech giant Apple has filed a patent for a "wearable ring device" with touchscreen and voice-control capabilities, paving the way for a potential launch of the Apple Ring.

Working in a similar way to the Apple Watch, the ring would respond to voice and gesture commands that could be used to control other electronic devices, according to the abstract from the patent document filed on 1 October 2015.

"A user controls an external electronic device with a finger-ring-mounted touchscreen that includes a computer processor, wireless transceiver, and rechargeable power source," the document said. "The ring is worn on a first finger receives an input from a second finger, selects one of a plurality of touch events associated with the input, and wirelessly transmits a command associated with the touch event to the external electronic device."

Biometric sensors could capture heart rate, perspiration levels and other similar data, replacing the need for an activity tracking wristband.

The device might also detect the writing motion of the user, potentially allowing it to digitally record hand-written notes.

Apple expects the ring to help users control their devices more efficiently.

"The use of touch-sensitive surfaces as input devices for computers and other electronic computing devices has increased significantly in recent years," said Apple's document.

"Use of existing touchpads and touch-screen displays, however, may be cumbersome, inconvenient, or inefficient for certain tasks and applications."

"There is a need for electronic devices with faster, more efficient methods and interfaces for interacting and/or controlling external electronic devices," it continued. "Such methods and interfaces optionally complement or replace conventional methods for interaction."

Rumours suggested that an "iRing" was being designed to operate the Apple television ahead of its launch in 2013, but it never materialised.

Images filed with the new patent depict various positions of small buttons and dials, along with sketches that show the screen both fully integrated into the band or as a larger element with the frame extended to wrap around it.

It looks like a scaled-down version of the Apple Watch, which was released last year but failed to impress the design world.

The ring would add to Apple's growing number of new products. Last month, reports emerged that the California-based company will launch an electric car in the next four years.

A stylus for technical drawing called Apple Pencil was revealed alongside the iPhone 6s and an Apple Watch collaboration with Hermès at the firm's annual conference.