Policymakers around the world are developing guidelines for use of artificial intelligence in health care. Baymax, the robotic health aide and unlikely hero from the movie Big Hero 6, is an adorable cartoon character, an outlandish vision of a high-tech future. But underlying Baymax's character is the very realistic concept of an artificial intelligence (AI) system that can be applied to health care. As AI technology advances, how will regulators encourage innovation while protecting patient safety? AI does not have a precise definition, but the term generally describes machines that have the capacity to process and respond to stimulation in a manner similar to human thought processes.