In March 2019 Patently Apple posted a report titled "Apple Invents a Bio-Authentication System for Apple Watch using Subepidermal Imaging that could be combined with Touch ID." Today, the U.S. Patent and Trademark Office officially granted Apple this patent.

The patent points to a future Apple Watch using an emerging new bio-authentication system that establishes patterns under the skin unique to a user. There are several biometric patterns Apple may choose from including vein, bone, and pigmentation.

Apple's invention covers systems and methods for an Apple Watch using a light field camera at the bottom of the watch that could be used as a user ID system.  The light field camera may be used to image a wrist of a user. The imaging may be performed from a dorsal side of the forearm that is shown in patent FIG. 5 further into this report.   

According to Apple, a synthetic focusing operation may be performed on a light field image obtained from the light field camera, to construct at least one image of at least one layer of the forearm near the wrist. A set of features of the forearm near the wrist may be extracted from the at least one image and compared to a reference set of features (e.g., a hair follicle pattern, a vascular pattern, a vein pattern, an artery pattern, a blood perfusion pattern in skin, a blood perfusion pattern in tendons, a blood perfusion pattern in fascia, a tendon pattern, a connective tissue pattern, a skin pigmentation pattern, a pore pattern, and/or a bone shape pattern obtained during a bio-authentication enrollment process performed for the user).

An operation (e.g., a bio-authentication operation, a bio-authentication enrollment operation, a secure transaction operation, a health monitoring operation, or a health assessment operation) may be performed in response to whether the set of features matches the reference set of features. In some embodiments, a tilt of the light field camera with respect to the dorsal side of the forearm may be determined and compensated for, prior to or while performing the synthetic focus operation.

Apple's patent FIG. 2 below shows an example of a watch including a biosensor system; FIG. 3 shows the watch of FIG. 2 attached to a forearm of a user near the user's wrist.

For more information, read our full March 2019 patent application report here or review Apple's granted patent 10,817,594 issued today.