An integrated position-sensing system for a MEMS-based cochlear implant

An interface providing multi-point microstimulation and position sensing has been developed for a cochlear prosthesis, integrating a MEMS-based electrode array with signal-processing electronics. The array incorporates piezoresistive polysilicon sensors for position and tip contact to minimize insertion damage and optimize implant placement. The signal-processing chip (2.4mm times 2.4mm) operates from 3V and performs command validation, stimulus generation, sensor selection, 5b offset compensation, and signal conditioning. The calibrated sensors have typical gauge factors of 15 and provide tip contact signals of more than 100mV