MIT engineers use a “natural battery” in the ear to power implant
Following in the same track of research into “ultra-low-power” medical devices as other MIT researches earlier this year, a team of researchers from MIT’s Massachusetts Eye and Ear Infimary (MEEI) demonstrated the ability to directly harness electrical energy from the inner ear without impairing hearing.
The cochlea, a portion of the ear unique to mammals, translates sound vibrations to the eardrum into electrochemical signals for the brain to process, making it into a “natural battery”. Although scientists have understood this process for years now, it was considered dangerous to attempt experimentation with the inner ear since it could result in a loss of hearing. This experiment is the first to demonstrate that it is possible to tap into this energy source without producing any hearing loss
The experiment was conducted by implanting electrodes into the cochlea of (actual) guinea pigs, and these electrodes were used to power an ultra-low-power radio transmitter in each guinea pig’s middle ear. In order to avoid disrupting hearing, the implanted device was designed to only use a small fraction of the electrochemical energy generated by the ear. Following the implantation, the guinea pigs demonstrated no change in capacity when administered hearing tests and the implanted devices was able to successfully transmit data.
Although these devices are still in their early experimental stages, they raise numerous future possibilities for use within humans. Application for implanted hearing aids is immediately obvious, but additional research is devoted to augmetics and ultra-low-power medical devices, a whole range of additional uses are likely to become available.