Friday, November 9, 2012

Powering medical devices with your ears

Researchers have discovered a way to harvest the power generated by a biological battery located in the inner ear to power electronics for medical applications. Patrick Mercier, who joined the Electrical and Computer Engineering faculty at UC San Diego Jacobs School of Engineering in July, said this natural battery could be used to power tiny, implantable electrodes that could monitor biochemical activities within the ear. This type of study has been difficult until now because of the risk of hearing loss associated with trying to biopsy the inner ear.  Mercier said using the technology to conduct basic scientific research on the inner ear could lead to transformative new knowledge about human hearing. It could also be used to power drug delivery pumps for therapies for hearing loss patients.

Another long-term implication is what this study says about the potential of low-power electronics. The natural battery in the ear doesn't provide much power, which is one of the reasons he said its capability has likely been left untapped since its discovery 60 years ago.  That meant the researchers had to develop a device that didn't require much power to function. In an experiment with guinea pigs, the researchers were able to use their “low-power energy harvester chip” (pictured) to power a small radio transmitter without causing any damage to the guinea pigs’ hearing. A major thrust of Mercier's research here at UC San Diego, will be developing electronics that consume "orders of magnitude" lower levels of power.  Mercier’s chip consumes approximately 1,000 times less power than a wristwatch, and approximately 1 billion times less power than a cell phone.

This work was published Nov. 8 in the journal Nature Biotechnology. Mercier conducted this study as part of his doctoral research at MIT in collaboration with a team of researchers led by Konstantina Stankovich and Anantha Chandrakasan from the Massachusetts Eye and Ear Infirmary (MEEI), the Harvard-MIT Division of Health Sciences and Technology, and MIT’s Microsystems Technology Laboratories.