The human body carries electrical signals well, and with technology developed by Purdue University engineers, they can be kept near the body.

You’ve seen it on TV, someone hacks a pacemaker or insulin pump – just by intercepting and analyzing wireless signals, the perpetrator could potentially kill you. This hasn’t happened in real life, yet, but researchers have been demonstrating for at least a decade that it’s possible.

Before the first crime happens, Purdue University engineers have tightened security on the network accessible by you and your devices using technology that keeps communication signals within the body.

“We’re connecting more and more devices to the human body network, from smart watches and fitness trackers to head-mounted virtual reality displays,” says Shreyas Sen, assistant professor of electrical and computer engineering at Purdue who specializes in sensing and communication systems. “The challenge has not only been keeping this communication within the body so that no one can intercept it, but also getting higher bandwidth and less battery consumption.”

Body fluids carry electrical signals very well and can use Bluetooth technology to send signals in and around the body. These electromagnetic waves can be picked up within at least a 10m radius of a person.


Sen’s team has demonstrated a way for human body communication to occur more securely – not going beyond 1cm off the skin and using 100x less energy than traditional Bluetooth communication. This is possible through a device that couples signals in the electro-quasistatic range, which is much lower on the electromagnetic spectrum. Sen’s group is working with government and industry to incorporate this device into a micro-sized integrated circuit.

Through a prototype watch, a person can receive a signal from anywhere on the body, from the ears to the toes, and thickness of skin or hair doesn’t make a difference in how well the signal carries. The idea would be to create a way for doctors to reprogram medical devices without invasive surgery. The technology would also help streamline the advent of closed-loop bioelectronic medicine – where wearable or implantable medical devices function as drugs but without the side effects – and high-speed brain imaging for neuroscience applications.

“We show for the first time a physical understanding of the security properties of human body communication to enable a covert body area network, so that no one can snoop important information,” Sen says.

Purdue University