Conventional wireless technologies such as Bluetooth and near-field communication perform poorly through the body, according to study senior author Alex Abramson, an assistant professor in Georgia Tech’s School of Chemical and Biomolecular Engineering. Such signals also require comparatively large antennas and substantial power, which can force implants to be physically larger than desired. SWANS instead uses tissue’s natural ionic conductivity as the communication pathway, transmitting small electrical pulses between devices that may be separated, differently positioned or implanted at widely separated locations.

Each implant can be programmed to respond to pulses distinguished by specific voltage and duration, allowing the network to activate selected devices selectively. Multiple implants can also be coordinated so that readings from several sensors produce a common trigger for an actuator. The system is intended primarily for modest amounts of information, such as the presence or absence of a biological signal or a yes-or-no instruction. More demanding data processing and larger exchanges occur in an external wearable hub, which coordinates the readings and commands sent through the body.

In an animal experiment, the researchers demonstrated coordinated movement of a rat’s two limbs through a network of sensors and neural interfaces. Sensors detected movement of the animal’s front paw, then autonomously triggered another device that stimulated and contracted a muscle in the hind leg, reproducing part of the pattern associated with natural walking. This was a preclinical demonstration in one rat rather than a test of a complete therapy in people. The investigators also developed implants smaller than 3 millimeters, small enough to pass through a syringe, using passive components that consume essentially no power while idle and activate when a triggering pulse arrives.

Power efficiency could support long implant lifetimes: the team estimated that an actuator triggered once per day could operate for about a year before replacement. In their experiments, the small electrical pulses produced no detectable damage in the tissue samples examined. The authors said the architecture could eventually be used to coordinate sensors and actuators throughout the body, including devices located deep within the stomach. Such possibilities remain development goals rather than demonstrated clinical capabilities, and the release did not report safety or performance trials in humans. Abramson and first author Ramy Ghanim nevertheless described the system as a step toward more coordinated bioelectronic medicine, in which a therapy could be delivered when and where it is needed.

Subject of Research: A body-tissue wireless network coordinating implantable sensors, actuators and wearable devices

Article Title: Engineers connect health wearables and implants using the body as the network

Article References: Engineers connect health wearables and implants using the body as the network. Original publication (Bibliographic details unavailable.)

Image Credits: AI Generated

DOI: Not provided

Keywords: implantable bioelectronics, wirebody networking, wearable devices, body tissue conductivity, neural interfaces, medical implants, low-power electronics, distributed sensors, bioelectronic medicine, rat motor control, Engineers, connect