Apple has filed two new patents for smart rings, which incorporate SMI sensing tech and hatpic controls for its Vision Pro headset.
Apple is still working on the technology for a smart ring release, while also developing cuffs designed for tracking fingers in mixed reality.
A patent filing spotted by Wareable goes into detail on how a ring device could track the wearer’s heart rate.
The filing describes a “self-mixing interferometry sensor” which would be deployed for detecting physiological conditions.
The SMI tech uses light configured to output towards the user’s skin to “detect displacements of the skin relative to the sensor, such as expanding and contracting of skin due to a user’s heartbeat,” the patent says.
“The data collected by the wearable device may be used to determine one or more physiological conditions for a user such as a heart rate.”
Most wearable devices with optical heart rate sensors use photoplethysmography (PPG) sensors, which utilise infrared LED lights to illuminate the skin to detect cardiac-related data.
Apple points out this is not always a perfect measurement. It says: “In many cases, the accuracy and/or quality of measurements from these sensor systems depends on light being transmitted into the skin to interact with one or more blood vessels. Thus, these sensors may be sensitive to positioning on the user and/or require robust circuitry to detect and/or processes the signals received from a user’s body.”
The involvement of an SMI sensor could provide a better solution, Apple says. It’s not entirely clear whether Apple would use the SMI sensor instead of or alongside the PPG sensor to improve heart rate measurements. Research has suggested SMIs would be useful either way (1) (2).
The key takeaway though, is that Apple is continuing to work on this technology with a potential Apple Ring (named Apple Loop, anyone?) on the horizon.
A previous filing in 2022, spotted by Patently Apple, also referenced SMI sensors within a finger-worn device as a means of recognising gestures, or the relative distance to a second device like an Apple Pencil, or positional data in AR or VR.
This brings us to the second filing, which goes beyond a ring and enters the realm of a finger worn device that sounds like a potential Vision Pro accessory, rather than a health wearable.
The new, 2024 patent describes a ring or U-shaped device equipped with force sensors that can detect the exertion of a finger push/press and transmit it to the VR/AR headset, while keeping the finger pad exposed to ensure the user can still feel what’s going on in the real-world environment.
The patent explains how haptic feedback provided by the cuffs could, for example, could replicate the sensation of tapping on a keyboard or mouse when working in an augmented/virtual environment. They could also be used to detect air taps or other gestures.
The patent reads: “A wearable device such as a finger-mounted device may be used to gather input from a user’s fingers as the user interacts with surfaces in the user’s environment and may be used to provide clicks and other haptic output during these interactions. The input that is gathered in this way may include information on how firmly a user is pressing against objects (finger press input), finger tap input associated with light taps of a user’s finger against a surface, lateral finger movement information such as shear force information indicating how firmly a user is pressing their finger sideways on a surface, and other user input.
“Haptic output may be provided to the user to confirm to the user that a light tap input has been recognized or to otherwise provide feedback to the user. The haptic feedback may provide the user with a sensation of tapping on a physical keyboard or other input device with a movable button member even when the user is tapping on a hard flat surface such as a tabletop”
While the patent focuses primarily on the force sensor, it states multiple other sensors for detecting motion, audio, heart metrics and a host of others.
The patent states: “If desired, device may include input-output devices other than force sensors. For example, device may include optical sensors, image sensors, status indicator lights and displays, may include buttons, audio components, sensors, sensors for detecting position, orientation, and/or motion, muscle activity sensors (EMG) for detecting finger actions, and/or other circuitry for gathering input.”
It shows that the smart ring is still an area of interest for Apple – but the fact that this latest patent focuses so much on haptics cools our hopes that the company could launch an Oura/Samsung rival.
