“Every once in a while an Apple patent application will surface in Europe that has bypassed the U.S. Patent Office for reasons unknown,” Jack Purcher reports for Patently Apple. “Late Thursday Patently Apple discovered a patent application covering Apple Watch that specifically discusses a multi-modal physiological sensing system.”

“In plain English, the patent is covering the Apple Watch Heart Rate Monitor,” Purcher reports. “And, it looks as though Apple may be introducing a new method for compensating for motion so that users could perhaps one day jog and swing their arms without affecting the heart rate readings as they do today.”

“To address the presence of motion artifacts, examples of the present disclosure can receive light information from each of two light guides, one in contact with the tissue of the user and one not in contact with the tissue of the user,” Purcher reports. “First light information can be obtained from the first light guide, and second light information can be obtained from the second light guide. A heart rate signal can then be computed from the first and second light information, for example, by using blind source separation and/or cross-correlation.”

Much more, including Apple’s patent application illustrations, in the full article here.