Testing wearable sensors as ' check engine' light for healt
A next step for smart watches and fitness trackers? Wearable gadgets gave a Stanford University professor an early warning that he was getting sick before he ever felt any symptoms of Lyme disease.

Geneticist Michael Snyder never had Lyme' s characteristic bulls-eye rash. But a smart watch and other sensors charted changes in Snyder' s heart rate and oxygen levels during a family vacation. Eventually a fever struck that led to his diagnosis....