Implants and wearables signal each other using body tissue as the conductor

What happened

Closed-loop therapies need sensors and stimulators in different parts of the body to talk to each other, but existing communication methods penetrate tissue inefficiently and need bulky components. Taking inspiration from the ionic signalling of the nervous system, the researchers built a platform that uses tissue itself as the conductive medium.

Devices generate transient electric fields. Another device responds only when the pulses it receives switch on its particular transistor circuit, which lets signals be addressed to specific implants. Communication worked among implants and wearables across epidermal, subcutaneous, intraperitoneal and gastrointestinal sites. The implants can be injected through a syringe, draw negligible power while listening, and gave more than ten times the tissue communication coverage of Bluetooth. In rats, the team demonstrated full-body networks of sensors and neural interfaces that enabled wireless motor control of two limbs.

Why it matters

Bioelectronic medicine is moving from single stimulators towards systems that sense in one place and act in another. A low-power way for small, injectable devices to coordinate through tissue removes a practical limit on building such networks.

Caveats

This entry is based on the abstract. The in vivo work was in rats, and the abstract gives no data rates, ranges in larger bodies, or assessment of whether the signalling fields affect surrounding excitable tissue.