Magnetic fields provide a new way to communicate wirelessly via the human body

Introduced by electrical engineers from the University of California, San Diego, a new wireless communication method works by sending magnetic signals through the human body, and offers a lower-power, more secure way to connect information between wearable electronic devices.

Communicating with wearable devices such as smartwatches, implanted smart monitors, or ingestible wireless sensors requires each to transmit a receiver using radio waves, usually done via Bluetooth or Wi-Fi, which typically require a lot of power.

While this method is still in development, the engineers hope to develop it into an ultra-low power wireless system that can easily transmit information around the human body, resulting in a wireless sensor network for full-body health monitoring.

“In the future, people are going to be wearing more electronics, such as smart watches, fitness trackers, and health monitors. All of these devices will need to communicate information with each other. Currently, these devices transmit information using Bluetooth radios, which use a lot of power to communicate. We’re trying to find new ways to communicate information around the human body that use much less power,” said Patrick Mercier, a professor in the Department of Electrical and Computer Engineering at UC San Diego who led the study.

To construct their model, the engineers used coils of copper wires insulated with PVC tubing, with one end terminating at a receiver and analyzer, and the other end of wires forming into three parts that wrap around the head, arms, and legs. The coils act as inductors for energy and allow the body to act as a wavelength for the magnetic fields.

An advantage of this system is that the magnetic fields are able to pass freely through biological tissues, and signals are communicated from arm to arm, arm to head, and arm to leg with 10 million times lower path losses than Bluetooth devices and much lower power consumption, ultimately leading to longer battery life.

“This technique, to our knowledge, 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,” said Mercier.

Another potential advantage of magnetic field human body communication is that it may offer more security than Bluetooth networks. Since Bluetooth radio communicates information over the air, anyone standing within a 30 foot radius can potentially eavesdrop and compromise a person’s privacy.

“Increased privacy is desirable when you're using your wearable devices to transmit information about your health,” said Jiwoong Park, a Ph.D student in Mercier’s Energy-Efficient Microsystems Lab.

Presented at the 37^th Annual International Conference of the IEEE Engineering in Medicine and Biology Society in Milan, Italy, the results of the research can be found in this paper.

Source: Gizmag