Soft wearable health monitor developed using stretchable electronics

Scientists have developed a wireless, wearable monitor using stretchable electronics that could allow long-term health monitoring without concern for skin injury or allergic reactions caused by conventional adhesive sensors.

The soft and conformable monitor can broadcast electrocardiogram (ECG), heart rate, respiratory rate and motion activity data as much as 15 metres to a portable recording device such as a smartphone or tablet computer.

The electronics are mounted on a stretchable substrate and connected to gold, skin-like electrodes through printed connectors that can stretch with the medical film in which they are embedded. "This health monitor has a key advantage for young children who are always moving, since the soft conformal device can accommodate that activity with a gentle integration onto the skin," said Woon-Hong Yeo, an assistant professor at the Georgia Institute of Technology in the US. "This is designed to meet the electronic health monitoring needs of people whose sensitive skin may be harmed by conventional monitors," Yeo said.

The monitor, described in the journal Advanced Science, has been studied on both animal models and humans. The monitor uses three gold electrodes embedded in the film that also contains the electronic processing equipment. The entire health monitor is just three inches in diameter, and a more advanced version under development will be half that size. The wireless monitor is powered by a small rechargeable battery, but future versions may replace the battery with an external radio-frequency charging system, researchers said.

Because the device conforms to the skin, it avoids signal issues that can be created by the motion of the typical metal-gel electrodes across the skin. The device can even obtain accurate signals from a person who is walking, running or climbing stairs. "When you put a conventional electrode on the chest, movement from sitting up or walking creates motion artifacts that are challenging to separate from the signals you want to measure," Yeo said. "Because our device is soft and conformal, it moves with the skin and provides information that cannot be seen with the motion artifacts of conventional sensors," he said.