By Phil Galewitz, KFF Health News Patients admitted to Houston Methodist Hospital get a monitoring device about the size of a half-dollar affixed to their chest — and an unwitting role in the expanding use of artificial intelligence in health care. The slender, battery-powered gadget, called a BioButton, records vital signs including heart and breathing rates, then wirelessly sends the readings to nurses sitting in a 24-hour control room elsewhere in the hospital or in their homes.