The ears might be the best place to gather vital signs, including energy expenditure and oxygen consumption, according to an article in the MIT Technology Review.
While most medical equipment manufacturers are concentrating on wristbands, some now think earbuds might prove to be a better home for biosensory technology.
Valencell, for example, has already developed ear-worn fitness-oriented sensors that might conceivably go on to have medical applications, while Intel and Apple are also understood to be investigating similar technology.
"If you had the right, good-quality earbuds, you could actually do a lot in terms of reading biological signals related to the health of a person," said Kevin Bowyer, chair of the University of Notre Dame computer science and engineering department.