Your smartwatch knows how many steps you took and how fast your heart beat, but it has almost no idea what your hands are doing. That blind spot matters, because hands are how people act on the world, and for amputees and patients in care settings, tracking hand and arm movement can be clinically meaningful. Engineers at Northwestern University's SPICE Lab say a standard smartwatch can do far more here than it does today.According to Northwestern's November 4, 2026 announcement, the lab has bui...