Jianbai Wang

"An Integrated Position-Sensing System for a MEMS-based Cochlear Implant"Nearly 100,000 people worldwide have received cochlear implants to date, where a bundle of wire electrodes (16-22) is inserted into the cochlea to electrically stimulate receptors in the auditory nerve, restoring hearing to the profoundly deaf. Replacing the traditional wire electrodes with MEMS-based higher-density thin-film arrays may not only allow significantly higher frequency discrimination but can also permit the inclusion of additional features such as position sensing (and eventually control).
A thin-film electrode array integrated with position sensors has been developed for a cochlear prosthesis. The array was fabricated using bulk micromachining technology, and it contains embedded poly-silicon piezoresistive sensors for wall contact and position in order to minimize tissue damage during array insertion and achieve deep implants after insertion. Nine position sensors are distributed at the tip and along the 8mm-long electrode array, and these sensors correspond to approximate gauge factors of 10-20, permitting array tip position to be determined within 50µm and providing wall contact output signals of more than 50mV at the tip. Moreover, parylene-silicon-dielectric electrodes were developed, improving the flexibility and maintaining enough robustness to facilitate the modiolus-hugging shape definition by a polymeric backing device.
The WIMS ERC is developing an implantable MEMS-based cochlear prosthesis using a hybrid electrode array. A custom integrated circuit (ASIC) mounts on the rear of a 32-site thin-film electrode array, interfacing with a hermetically-packaged WIMS microcontroller and wireless chip over an 8-lead polymeric cable. The 2.4mm x 2.4mm ASIC chip operates from 5V and performs command validation, stimulus generation, sensor selection, 5b offset compensation, and signal conditioning (amplification and band-limiting).

Location: Hedco Neurosciences Building (HNB) - 100

Audiences: Everyone Is Invited

Contact: Ericka Lieberknecht