This Tiny Patch Keeps Track of Your Heart and Body Chemistry at Once

By Jamie Condliffe on at

This little device could one day replace heart rate monitors. The researchers behind it claim that it’s the first flexible wearable device able to measure both electrical heart signals and biochemical markers while you work out.

Developed by a team from the University of California San Diego, the device is able to record an electrocardiogram of your heart’s activity and levels of lactate, a chemical that correlates with physical exertion, at the same time. The circuitry is printed on to a thin and flexible polyester sheet, with a small on-board chip used to beam the data to a nearby device using Bluetooth.

The team explains in Nature Communications that the biggest difficulty with creating such a device is ensuring that the signals being acquired don’t interfere with each other. Because the device is so small and thin, it’s easy for the electrical signals to generate cross-talk in the circuits that sit close to each other. Ultimately, the team placed the EKG electrodes 3.8 centimetres apart with the lactate sensor in the middle to minimise noise.

In a series of tests which saw the device used during 30-minute workouts, the sensor was found to provide heart rate data which closely matched a normal heart rate monitor. Now, the team is going to investigate if the same device can be used to measure other vital signs.[Nature Communications]