Ultra Low-Power Wireless

A new wireless communication technique could greatly reduce the power requirements for wearable devices while offering greater security of data. It works by using the human body to transmit magnetic signals between devices and has been shown to achieve the lowest path losses (signal obstructions) of any system demonstrated to date. The most obvious application is for development of a full-body, wireless sensor network for health monitoring.

Most wearable devices currently use electromagnetic radiation (EMR) such as Bluetooth to transmit data, however EMR does not pass easily through the body. As a result, the signals require a power boost, which means shorter battery life. On the other hand, magnetic fields – which are already widely used in magnetic resonance imaging (MRI) and implantable devices – pass readily through human tissue, so a power boost is not needed. The path losses using magnetic field communication are estimated to be 10 million times lower than those associated with EMR.

Because the power levels are so low, the researchers claim that there are no significant health risks with magnetic wireless. In addition, using the human body as a communication medium means greater security of medical data. Unlike EMR which is transmitted through the air and can potentially be intercepted by anyone within 30 feet, a magnetic wireless signal would not be radiated off the body nor transmitted from one person to another. This method will work with any device that has a circular geometry, which is needed to generate the magnetic field. This includes wristbands, headbands and chest straps, but not patch-type devices or clip-on sensors.