SoC can be a fully implantable hearing aid

Massachusetts Institute of Technology research has led to a fully implatable cochlear hearing device. A paper presented by Markus Yip at the 2014 International Solid State Circuits Conference (ISSCC) in San Francisco described the system's SoC, the piezoelectric acoustic sensor, and the neural stimulator and electrode array. The system uses a wireless power scheme developed elsewhere.

A piezoelectric sensor mounted at the umbo in the middle ear picks up sound and its signal goes to an analog front end and A/D and then to the processor, which uses continuous wave interleaved sampling with an eight channel filer bank. This entire process takes just a few hundredmicrowatts. After that comes the neural simulator and implanted electrode array at the cochlea which requires around 500 µW. The waveforms received by the electrodes stimulate auditory nerve fibers and make the sound audible to the user.

“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,” says Anantha Chandrakasan, MIT Professor of EE. “Or you could imagine a smart pillow, so you charge overnight.” Harvard Medical School and Massachusetts Eye and Ear Infirmary were involved with the research. For more information, see http://web.mit.edu/newsoffice/2014/cochlear-implants-with-no-exterior-hardware-0209.html