IMEC researchers have developed a wireless electrocardiography (ECG) patch capable of continually monitoring heart rate, the Engineer reports. The first of its kind, the patch is roughly 3" x 1" and can attach to any part of the body, transmitting heart rate info to a receiver up to 30 feet away.
Multiple patches can also serve as electromyography (EMG) system, delivering info about muscle activity. If only monitoring heart rate, the rechargeable lithium-ion battery can power the unit for several days--less so for EMG mode. (More heart stories.)