A Neural Stimulation IC Based on a Reconfigurable Current DAC with In-Situ Neural Recording Function for Cochlear Implant Systems

According to the WHO report, the hearing-impaired population in the world is about 470 million in 2019, and about 15 million people could hear sounds with cochlear implants (CIs). In clinical practices, people who have a hearing loss greater than 90dB are guided to use CIs instead of hearing aids to restore hearing. The CI delivers electrical stimulation to auditory nerves through an electrode array which is surgically inserted in a cochlea. The multiple electrodes in the array are placed at different locations in the cochlea and deliver electrical pulses with different strengths and frequencies from each other to convey sound information. The sound information is driven by a sound processor that is worn on a user’s head. The sound processor receives and processes sound signals picked up by microphones, and the processed sound signals are transferred to an implant unit wirelessly through inductively coupled coils. The implant unit then performs electrical stimulation through the electrode array according to the received data. The CI also monitors neural responses and impedances at the electrodes as feedback and transmits these measured data back to the sound processor.