Magnetic sensors to offer low-power answer to full-body wireless communication
Tue 1 Sep 2015

A team of electrical engineers at the University of California, San Diego, has presented its findings on a new technology which can pass magnetic signals through the human body, offering an advancement for wireless communication between wearable devices.
The technique, which has been successfully demonstrated, could provide an alternative to existing wireless technologies, providing a lower-power and more secure way of communicating information than Bluetooth for example.
The researchers are currently looking at developing a system of wireless sensors to support full-body health monitoring, connecting devices such as smart watches, fitness bands and medical wearables.
“Currently, these devices transmit information using Bluetooth radios which use a lot of power to communicate. We are trying to find new ways to communicate information around the human body that use much less power,” said electrical and computer engineering professor Patrick Mercier.

Magnetic field-generating coils (http://www.jacobsschool.ucsd.edu/news/news_releases/release.sfe?id=1807)
Bluetooth technology uses electromagnetic radiation to communicate data, but the signals do not easily through the body, requiring increased power in order to overcome any ‘path loss’ or obstruction.
The new technique outlined by the team involves magnetic fields which can easily pass through biological tissue. The engineers showed that the ‘path loss’ linked with the new magnetic technology was over 10 million times lower than with Bluetooth radio signals.
“This technique achieves the lowest ‘path losses’ out of any wireless human body communication system that’s been demonstrated so far. This technique will allow us to build much lower power wearable devices,” Mercier explained, adding that the lower power consumption would also increase battery life.
The researchers did confirm that the technique would not pose any risks to a wearer’s health and would be completely secure. “Increased privacy is desirable when you are using your wearable devices to transmit information about your health,” the report noted.
However, as seen with Apple’s iWatch, it is unclear whether tattooed skin would interfere with the magnetic component of the technology.