A dispute over the patent for the blood-oxygen sensor in the two newest Apple Watch models is at the heart of the pause, which partly goes into effect on December 21. A dispute over the patent for the blood-oxygen sensor in the two newest Apple Watch models is at the heart of the pause, which partly goes into effect on December 21. Read More Gear, Gear / Gear News and Events, Gear / Products, Gear / Products / Health and Fitness, No More Wrist-mas Wired