Mobile phones could someday wirelessly charge cochlear implants

A newly-developed low-power chip that will be shown off later this week could help people with cochlear implants ditch the hardware they currently have to affix to the outside of their ear, further easing use of the hearing-restoring devices.
Current cochlear implants use small batteries, similar to the ones used in watches, that must be replaced or recharged periodically. The new chip works with a battery that recharges wirelessly in two minutes, which gives it enough juice to last for eight hours.
“The idea with this design is that you could use a phone, with an adapter, to charge the cochlear implant, so you don’t have to be plugged in,” MIT electrical engineering professor Anantha Chandrakasan said. “Or you could imagine a smart pillow, so you charge overnight, and the next day, it just functions.”
The research team, which is composed of scientists from the MIT Microsystems Technology Laboratory, Harvard Medical School and the Massachusetts Eye and Ear Infirmary, will show a prototype charger at a conference this week.
But the new chip goes beyond just getting rid of charging hardware. It could allow implant recipients to avoid having to wear electronics on the outside of their head at all. That’s because it takes advantage of ossicles–a type of bone in the ear–which vibrates when there is noise. The chip is paired with a sensor to detect and convert those vibrations into electrical signals, which restores hearing without any sort of external microphone. This kind of system is only possible because of the use of such a low-power chip.
Researchers are interested in bringing wireless charging to all kinds of implants. Pacemakers, for example, need to be surgically removed and replaced every time they need their battery switched out. But it’s possible that devices like cochlear implants won’t need an external source of power at all in the future. In 2012, the MIT/Harvard team also created an implantable electronic device that draws energy from a chamber in the inner ear that is rich with ions.
Featured image from Thinkstock/Ninell_art