ALEXANDRIA, Va., Dec. 31 -- United States Patent no. 12,507,918, issued on Dec. 30, was assigned to Nokia Technologies Oy (Espoo, Finland).
"Photodetector apparatus" was invented by Pellervo Ruponen (Helsinki) and Kim Blomqvist (Espoo, Finland).
According to the abstract* released by the U.S. Patent & Trademark Office: "An apparatus, such as a photoplethysmographic sensor, including a light source configured to illuminate a target, wherein the apparatus is configured to receive incident light reflected from or transmitted through the target. The apparatus includes also a reflective element configured to direct at least part of the received incident light to a focus point, and a photodetector configured to receive light from the focus poin...