Wireless power transfer deep inside the body runs medical devices and sensors

May 23, 2014 // By Paul Buckley
A Stanford University electrical engineer has invented a way to transfer wireless power deep inside the body to run pacemakers, nerve stimulators or sensors.

The discoveries made by Ada Poon, assistant professor of electrical engineering at Stanford University, are reported in the Proceedings of the National Academy of Sciences and focus on Poon's years of work to eliminate the bulky batteries and clumsy recharging systems that often stop medical devices from being more widely used.

The power technology could provide a path toward a new type of medicine that allows physicians to treat diseases with electronics rather than drugs.

"We need to make these devices as small as possible to more easily implant them deep in the body and create new ways to treat illness and alleviate pain," explained Poon.

Poon's team built an electronic device smaller than a grain of rice that acts as a pacemaker. The device can be powered or recharged wirelessly by holding a power source about the size of a credit card above the device, outside the body.

The central discovery involves the creation of a new type of wireless power transfer – using roughly the same power as a cell phone – that can safely penetrate deep inside the body. An independent laboratory that tests cell phones found that Poon's system fell well below the danger exposure levels for human safety.

Poon's lab has tested the wireless charging system in a pig and used it to power a tiny pacemaker in a rabbit. She is currently preparing the system for testing in humans.